A Brief History of Wires in the Brain

Metaphors have formed a significant part of the development of neuroscience, often linked with technology. A metaphor that has been widely used for the past two centuries is that of the nervous system being like wires, either as a telegraph system or telephone exchange, or, more recently, in the more abstract metaphor of a wiring diagram. The entry of these terms into scientific writing is traced, together with the insights provided by these metaphors, in particular in relation to recent developments in the study of connectomes. Finally, the place of the wiring diagram as a modern version of Leibniz’s “mill” argument is described, as a way of exploring the limits of what insight the metaphor can provide

Research on Secondary Cable Identification Based on the Principle of Electromagnetic Induction

When the operation and maintenance station performs cable maintenance, installation measures, etc., due to the lack of direct and effective tools, and the complicated wiring of the operation and maintenance station equipment, the wiring diagram is inconsistent with the actual situation, which brings risks to the removal of waste cables. As an indispensable safety tool in the power industry, the cable identification device is an important means to ensure the safety of maintenance personnel. In view of the current situation, this paper analyzes the electric field around the cable line of the operation and maintenance station, and simplifies the simulation of the line, and proposes a secondary cable identification device based on the principle of electromagnetic induction, which can quickly identify the target cable, which greatly improves the cable identification performance. Efficiency reduces the time for cable identification and improves safety.

Hippocampus-striatum wiring diagram revealed by directed stepwise polysynaptic tracing

The hippocampus and the striatum represent two major systems in the brain for learning, memory and navigation. Although they were traditionally considered as two parallel systems responsible for distinct types of learning or navigation, increasing evidence indicates a close synergetic or competitive interaction between them. Both the hippocampus and the striatum consist of multiple anatomical and functional domains. Besides the limited direct projection from the hippocampus to the ventral striatum, most of the functional interaction between them may be mediated by polysynaptic projections. Polysynaptic connectivity has been difficult to examine due to a lack of methods to continuously track the pathways in a controlled manner. Here we developed a novel approach for directed stepwise polysynaptic tracing by reconstituting a replication-deficient retrograde transneuronal virus – pseudorabies virus lacking gene IE180 (PRVΔIE). We minimized PRV neurotoxicity by temporally restricting viral replication; and enabled both anatomical tracing and functional analysis of the circuits. With these tools, we delineated a hippocampus-striatum wiring diagram, which consists of pathways from specific functional domains in the hippocampus to corresponding domains in the striatum via distinct intermediate regions. This polysynaptic wring diagram provides a structural foundation for further elucidation of the interaction between the hippocampus and the stratum in multiple brain functions.Significance StatementWe created a new method for controlled stepwise tracing of polysynaptic neuronal circuits which also enables functional analysis of the circuits. With this method, we revealed the polysynaptic wiring diagram between the hippocampus and the striatum, two major brain structures centrally involved in learning, memory and spatial navigation. This wiring diagram demonstrates how specific anatomical domains in the hippocampus are connected to the specific domains in the striatum via distinct intermediate brain regions; thus it will help to elucidate the functional interaction between these two major memory and navigation systems. Our new method can be broadly applied to many other brain circuits for anatomical and functional analysis.

Circuit organization of the excitatory sensorimotor loop through hand/forelimb S1 and M1

Sensory-guided limb control relies on communication across sensorimotor loops. For active touch with the hand, the longest loop is the transcortical continuation of ascending pathways, particularly the lemnisco-cortical and corticocortical pathways carrying tactile signals via the cuneate nucleus, ventral posterior lateral (VPL) thalamus, and primary somatosensory (S1) and motor (M1) cortices to reach corticospinal neurons and influence descending activity. We characterized excitatory connectivity along this pathway in the mouse. In the lemnisco-cortical leg, disynaptic cuneate→VPL→S1 connections excited mainly layer (L) 4 neurons. In the corticocortical leg, S1→M1 connections from L2/3 and L5A neurons mainly excited downstream L2/3 neurons, which excite corticospinal neurons. The findings provide a detailed new wiring diagram for the hand/forelimb-related transcortical circuit, delineating a basic but complex set of cell-type-specific feedforward excitatory connections that selectively and extensively engage diverse intratelencephalic projection neurons, thereby polysynaptically linking subcortical somatosensory input to cortical motor output to spinal cord.

RANCANG BANGUN MESIN LAS TIG SEMI OTOMATIS BERBASIS ARDUINO UNO

Mesin las TIG semi otomatis berbasis Arduino Uno merupakan alat yang dirancang untuk mengontrol parameter kecepatan pengelasan yang sesuai dengan pekerjaan yang akan dilakukan. Proses pembuatan alat ini meliputi perancangan alat dan proses fabrikasi, wiring diagram, dan desain Arduino Uno, serta proses uji coba pengelasan. Pengujian alat pengelasan TIG dilakukan pada plat baja SS400 dengan ukuran 18 × 10 × 3 mm, arus sebesar 80 A, gas pelindung Argon, dan panjang busur las 2 mm, dengan variasi kecepatan pengelasan sebesar 4 mm/detik, 6 mm/detik dan 8 mm/detik. Hasil pengelasan yang paling baik dan sesuai didapatkan pada kecepatan pengelasan 6 mm/detik. Hal tersebut disebabkan karena kecepatan pengelasan dan besar arus yang digunakan sesuai, sehingga minim cacat lasan

Circuit organization of the excitatory sensorimotor loop through hand/forelimb S1 and M1

Sensory-guided limb control relies on communication across sensorimotor loops. For active touch with the hand, the longest loop is the transcortical continuation of ascending pathways, particularly the lemnisco-cortical and corticocortical pathways carrying tactile signals via the cuneate nucleus, ventral posterior lateral (VPL) thalamus, and primary somatosensory (S1) and motor (M1) cortices to reach corticospinal neurons and influence descending activity. We characterized excitatory connectivity along this pathway in the mouse. In the lemnisco-cortical leg, disynaptic cuneate→VPL→S1 connections excited mainly layer (L) 4 neurons. In the corticocortical leg, S1→M1 connections from L2/3 and L5A neurons mainly excited downstream L2/3 neurons, which excite corticospinal neurons. The findings provide a detailed new wiring diagram for the hand/forelimb-related transcortical circuit, delineating a basic but complex set of cell-type-specific feedforward excitatory connections that selectively and extensively engage diverse intratelencephalic projection neurons, thereby polysynaptically linking subcortical somatosensory input to cortical motor output to spinal cord.

PERANCANGAN AWAL FLIGHT TEST INSTRUMENTATION (FTI) UNTUK PESAWAT TERBANG TANPA AWAK DI PUSTEKBANG LAPAN

Abstrak--Pesawat terbang tanpa awak (PTTA) yang dikembangkan oleh LAPAN memiliki maximum takeoff weight (MTOW) yang bervariasi. PTTA ini memiliki sistem kendali (SK) yang menjadikannya dapat terbang secara auotonomous. Salah satu sub sistem inti yang ada di dalam SK adalah flight control law (FCL), dimana pengembangannya dimulai dari tahap penentuan requirement dilanjutkan dengan tahap desain SK. Dalam desain SK, tahapan metode yang digunakan adalah software in the loop simulation, hardware in the loop simulation dan uji terbang. Untuk mengetahui apakah FCL yang dikembangkan telah memenuhi requirement awal yang didefinisikan, perlu sebuah alat yang mampu merekam parameter-parameter penting selama uji terbang, yang dinamakan dengan flight test instrumentation (FTI). Pada penelitian ini, akan dibahas mengenai requirement awal yang harus dipenuhi oleh FTI, mulai dari dimensi, berat, jumlah parameter yang direkam, serta kemampuan hardware & sensor. Tahapan selanjutnya adalah melakukan market study pemilihan hardware dengan metode pembobotan dan diakhiri dengan desain arsitektur serta wiring diagram FTI. Dari hasil penelitian yang dilakukan, diperoleh desain awal FTI yang memiliki berat total kurang dari 1.5Kg dan dimensi yang bisa dimasukkan ke dalam PTTA dengan MTOW 10Kg. FTI ini juga dilengkapi dengan baterai dan sensor yang independen, sehingga tidak tergantung dan membebani system elektronik yang terdapat pada PTTA Kata Kunci : FTI, Identifikasi Parameter, PTTA